Buphthalmum: Planting and Cultivation

Description and Botany

The Buphthalmum or Willow-leaved Ox-eye, sometimes nicknamed “ox-eye”, is a perennial plant from the Asteraceae family, like daisies and asters. Only the species Buphthalmum salicifolia is cultivated for ornamental purposes in our gardens, but it has given rise to a few varieties such as the Buphthalmum salicifolium ‘Dora’.

Buphthalmum, botanical plate from 1878

It is found in the wild at the edge of woods or in sunny, dry, and rocky meadows, in the Alps, the Jura, and Alsace, sometimes up to 1800 m in altitude and in certain regions of Central Europe. This is a very vigorous perennial, capable of withstanding drought as well as frost, down to -29°C.

From a woody stump, the plant develops a bushy clump with a dense and upright habit in spring. It reaches 25 to 60 cm in height.

The numerous simple or branched stems, robust and rough, bear deciduous foliage of a bright matte green colour. The leaves that punctuate them are lanceolate, narrow like those of a willow, and slightly dentate, hence its vernacular name “salicifolia”, meaning willow in Latin. Arranged alternately along the stems, they measure about ten centimetres in length.

On this light vegetation, all summer long, from June-July to September, numerous small golden-yellow daisy-like flowers bloom tirelessly. The slender flower stems then bear an abundance of solitary floral heads, about 5 cm in diameter. They are formed of filiform, pointed, and fringed ligules at their tips, radiating around a sunny yellow central disc. The collar spreads almost horizontally.

This generous flowering is melliferous and attracts pollinating insects, such as butterflies and bees. It is one of those plants that contribute to natural biodiversity. Once the flowering is over, the discs turn brown to make way for seeds.

Buphthalmum salicifolium clump of leaves and close-up of the flowering; on the right, Buphthalmum speciosum (© Leonora Enking)

Main species

Buphthalmum salicifolium Dora

This is the type species! It is prized for its cultivation in dry soil and its generous flowering.

• Flowering time July to September
• Height at maturity 60 cm

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Planting Buphthalmum

Where to Plant It?

The Buphthalmum salicifolium is exceptionally easy to grow. It tolerates extreme temperature fluctuations: intense heat as well as harsh frosts. Hardy to at least -25°C, it thrives in all regions. Highly adaptable to soil types, it will flourish in well-drained garden soil that remains relatively moist during summer, though it can also tolerate ordinary, occasionally dry and stony, even chalky soil. For abundant flowering, some soil moisture is preferable. While it can withstand occasional drought and intense heat, it dislikes waterlogged soil in winter.

Choose a spot in full sun, or light shade in the most exposed regions of the country.

Its rustic, cheerful appearance and medium size make it ideal for borders and mixed borders, or to brighten the base of a sunny wall, as well as planters and pots, as it also adapts well to container gardening.

When to Plant Buphthalmum salicifolium?

The best time to plant is in spring, from February to April, or in autumn, from September to November, avoiding drought periods and ensuring all risk of frost has passed.

Buphthalmum salicifolium

How to Plant It?

In the Ground

Soil rich in organic matter will encourage abundant flowering. In very poor soil, we recommend adding well-rotted compost.

• Soak the bucket in a pail of water to moisten the root ball
• Dig a hole 2 to 3 times the size of the bucket
• If needed, improve drainage by spreading a layer of gravel, clay pebbles, or pumice at the bottom of the hole
• Mix one or two handfuls of compost with garden soil
• Place the root ball and fill in without burying the collar
• Firm the soil very lightly
• Water regularly after planting, especially if the season is dry

In a Pot

Choose a pot 30 to 50 cm in diameter with drainage holes at the bottom.

• Spread a generous layer of drainage (gravel or clay pebbles) at the bottom of the pot
• Fill the pot with a mix of garden soil (1/2), flowering plant compost (1/2), and a handful of compost
• Plant without burying the collar and fill in
• Water very regularly, never letting the growing medium dry out

Cultivation and Care

Once well established, the Buphthalmum requires little care. It appreciates a soil that remains cool during the summer, especially in the first few years, and will tolerate temporary drought better over time. The base should remain cool, particularly during periods of growth and flowering. In case of extreme heat, water regularly but avoid overwatering. You can mulch in May to ensure the base stays sufficiently cool in summer.

Every spring, add two or three handfuls of mature compost around the base with light raking.

In pots, monitor watering more closely during the growing season as the soil dries out more quickly. Allow the substrate to dry out between waterings. You may also apply a flowering plant fertiliser in spring and summer. Repot your plant annually in fresh compost.

In summer, remove faded flowers as they appear to prolong flowering.

After flowering, cut back the stems to 15 cm above the soil using shears.

Every two years, in spring or autumn, divide the clumps to rejuvenate them.

Diseases and potential pests

Robust, it is simply endangered by slugs and snails, which can be fond of its young shoots in spring. Discover our tips for naturally combating gastropods.

Multiplication

The simplest method to propagate buphthalmum is by dividing the clump, preferably done in early spring.

1. With a sharp spade, lift the clump
2. Cut out a few sections, preserving as many roots as possible
3. Replant immediately in the desired location in well-prepared soil
4. Water and mulch

Combining in the garden

The radiantly beautiful flowers of the Buphthalmum bring vibrancy and simplicity to the garden. With their rustic charm, they integrate perfectly into natural and naturalistic gardens, alongside other easy-going perennials.

If possible, plant them in clusters. Within a summer flower bed, they will form colourful swathes among summer-flowering perennials with warm hues. They can be paired with other daisy-like flowers, such as Echinacea, Rudbeckia, yellow daylilies, Heliopsis helianthoides ‘Mars’, Leucanthemum ‘Banana Cream’, or even Gaillardia. Dahlias (like the Dahlia ‘Kelvin Floodlight’) will also make excellent companions. A few clumps of ornamental grasses, such as Miscanthus, will add a soft touch to this lush scene.

Rudbeckias, yellow Dahlias, Miscanthus sinensis ‘Variegatus’, and yellow daylilies accompany the sunny flowering of Buphthalmum

Flowers with cool hues, such as Siberian Sage, Verbena bonariensis, Asters, and Veronicastrums, will create an effective yellow/blue contrast.

In borders, they will shine alongside small Helenium, dwarf Dahlias (Happy Single), Sage, and dark-leaved Heuchera (Heuchera ‘Black Pearl’), which will enhance its warm tones by creating a colourful frame at its base.

Buphthalmum, paired with Verbena bonariensis, Veronicastrums, and Asters for a yellow and blue scene